Graphene-based heterojunction for enhanced photodetectors

Abstract

Graphene has high light transmittance of 97.7% and ultrafast carrier mobility, which means it has attracted widespread attention in two-dimensional materials. However, the optical absorptivity of single-layer graphene is only 2.3%, and the corresponding photoresponsivity is difficult to produce at normal light irradiation. And the low on–off ratio resulting from the zero bandgap makes it unsuitable for many electronic devices, hindering potential development. The graphene-based heterojunction composed of graphene and other materials has outstanding optical and electrical properties, which can mutually modify the defects of both the graphene and material making it then suitable for optoelectronic devices. In this review, the advantages of graphene-based heterojunctions in the enhancement of the performance of photodetectors are reviewed. Firstly, we focus on the photocurrent generation mechanism of a graphene-based heterojunction photodetector, especially photovoltaic, photoconduction and photogating effects. Secondly, the classification of graphene-based heterojunctions in different directions is summarized. Meanwhile, the latest research progress of graphene-transition metal dichalcogenide (TMD) heterojunction photodetectors with excellent performance in graphene-based heterostructures is introduced. Finally, the difficulties faced by the existing technologies of graphene-based photodetectors are discussed, and further prospects are proposed.

Band Gap Engineering of AlYN Films for Solar-Blind Ultraviolet Photodetection

“…Gr has been recognized as an ideal material for fabricating heterojunctions due to its good optical properties and high mobility, with transmittance greater than 90% in the SBUV range. − In this work, based on the AlYN films with a band gap of 4.7 eV, a SBUV detector with a p -Gr/ i -AlYN/ n -Si structure was prepared, as Gr was taken as the upper conductive layer. Relevant characterizations on this device are listed in Figure .…”

The Rise of Graphene Photonic Crystal Fibers

“…Graphene can be combined with hBN, TMDs (MX 2 , M = Mo, W; X = S, Se, Te), and other 2D materials to form a heterojunction with unusual physics and properties. [ 224,225 ] For example, TMDs with exotic optical and electronic properties are combined with graphene with wide spectral response range, which could extend the optical spectra of photodetection and light emitting in fibers. Based on the high nonlinearity of graphene and hBN, hybrid optical fibers based on graphene‐hBN heterostructure could be applied to generate supercontinuum white light, wavelength conversion, high‐harmonic generation, nonlinear parametric amplification, optical soliton generation, and other optical effects.…”

High-sensitivity hybrid MoSe2/AgInGaS quantum dot heterojunction photodetector

“…16 The graphene photodetectors do not satisfy the requirements of high-response optoelectronic devices due to the large dark current. 17 Hence, two-dimensional transition metal dichalcogenide (2D TMDC) semiconductors exhibit appealing properties, such as tunable bandgaps, high electron mobility, exibility, and the absence of dangling bonds on their surfaces. [18][19][20][21][22][23] These characteristics enable 2D TMDCs to be an excellent candidate for the high-performance photodetector.…”